Guide piece and method for mounting to a chassis in multiple orientations

ABSTRACT

A guide piece molded out of a rigid but slightly resilient material, such as plastic, having an elongated body with a U-shaped channel, used to hold an edge of a printed circuit card, extending the length of the guide piece to form an opening on each end. The guide piece has a plurality of raised tabs along the external surface of one leg of the channel and middle and end nubs on the external surface of the other leg of the channel. The raised tabs mate with fingers formed in a chassis, and the middle and end nubs mate with holes in the chassis. The combination of the raised tabs mating with fingers, and the middle and end nubs mating with the holes, secures the guide piece to the chassis, without requiring protrusions through the chassis.

This is a divisional of application Ser. No. 08/741,499, filed Oct. 31,1996 now U.S. Pat. No. 5,738,266.

FIELD OF THE INVENTION

This invention relates to electronic hardware equipment contained in achassis and more particularly to securing electronic components to theinterior of a chassis. Even more particularly, the invention relates toa plastic guide piece and method of mounting the guide piece to theinterior of a chassis for receiving electronic circuit cards.

BACKGROUND OF THE INVENTION

Industrial electronic hardware equipment has typically been designed toallow easy access to the electronic components contained inside thechassis for testing, repair, and replacement purposes. It is desirablethat individual electronic circuit cards be easily installed andremoved. Securing electronic circuit cards inside the chassis andallowing easy installation and removal is accomplished by attachingplastic guides to the interior of the chassis. The plastic guides aretypically used in pairs and are affixed to opposite sides of a chassisfacing each other. The plastic guides are grooved so that opposite edgesof an electronic circuit card may be inserted into the groves and becomeseated securely between the opposing pairs of plastic guides. Theplastic guides may be attached to a chassis with the grooves orientedhorizontally or vertically. A single plastic guide may also be used tosecure one edge of an electronic circuit card. The other edge may besecured in some other fashion. For example, a single plastic guide maybe used in conjunction with an expansion slot bracket found in manypersonal computers which is screwed into the back of the frame of thechassis. Additionally, plastic guides may be used to hold a metal plateor tray which in turn holds an electronic circuit card.

Plastic guides have been made in various sizes and shapes depending uponchassis location and orientation required to receive an edge of anelectronic circuit card. Various approaches have been utilized inattaching plastic guides to a chassis. One approach utilizes a rivet-onplastic guide. This requires a rivet part and access to the exteriorsurfaces of the chassis for installation purposes. The rivets protrudefrom the exterior surfaces of the chassis and thus require clearancesaround the exterior of the chassis. These rivet protrusions can bescraped, bumped, or caught on objects brought near the vicinity of theexterior of the chassis. This may cause the rivets to break and theplastic guide to become unsecured from the chassis. Additionally, thestress in the rivets over time may cause cracking of the plasticresulting in breakage, thus causing the plastic guide to becomeunsecured from the chassis. Replacing a rivet-on plastic guide that hasfailed is difficult due to the chassis being full of electroniccomponents and the access to the exterior surfaces of the chassisrequired to use the rivet tool. Also, if a rivet-on plastic guide needsto be removed for some reason, the rivet connection must be severed orbroken. Once removed, the plastic guide is not reusable.

Another approach uses a snap-on plastic guide. Typically the plasticguide has one or more protrusions on its surface that are forced throughopenings in the chassis. These protrusions are designed so that theyeither expand after insertion or have an initial larger diameter portionthan the opening they have been forced through, thus securing theplastic guide piece to the chassis. This functional approach, however,makes it difficult to remove the plastic guide once it has been snappedinto place. Once removed, the plastic guide may be so damaged that itmay not be reusable and another plastic guide must be used in its place.Additionally, the protrusions through the surface require clearances onthe outside surfaces of the chassis, making them susceptible to the samebreakage problems associated with rivet-on plastic guides.

An additional approach utilizes a plastic guide piece with a "T" shapedprotrusion that engages a keyhole type slot in the chassis. The top ofthe "T" inserts in the slot. The guide is then moved laterally engagingone arm of the "T" over the outer surface of the chassis, preventing theplastic guide from moving perpendicular to the chassis surface. In someinstances the plastic guide may also have a bump or other protrusionthat engages or snaps into a hole or some other detail to preventmovement of the plastic guide in a direction parallel to the chassissurface.

In some instances, rivet-on, snap-on, or keyhole type plastic guides arenot practical because of the shape of the chassis and requiredorientation of the plastic guides, such as in a corner offset. In suchcases, protrusions through the surface of the chassis may be highlyundesirable or not even feasible.

It is thus apparent that there is a need in the art for an improvedapparatus and/or method which solves the problems of the current art.There is a need in the art for one universal guide piece that may besecured to the interior of a chassis in multiple orientations so thatelectronic circuit cards may be inserted horizontally or vertically.There is also a need in the art for a plastic guide that does notrequire access to the exterior surfaces of the chassis for installation,that does not require the use of rivets or other protrusions through thesurface of the chassis, and does not require clearance on the outersurface for attachment devices. There is further need in the art for aplastic guide that is easily installed and removed, that is not damagedin the removal process so that the plastic guide can be used over andover again, and that does not require the use of any special tools forinstallation or removal. There is a still further need in the art for aplastic guide that is not susceptible to breakage either from bumping orscraping of exterior protruding attachment devices or stress in theattachment device itself and that can be located in an interior corneroffset without protrusions. The present invention meets these and otherneeds in the art.

SUMMARY OF THE INVENTION

It is an aspect of the present invention to attach a guide piece usedfor receiving electronic circuit cards internally to a chassis inmultiple orientations.

It is another aspect of the invention that the guide piece be universalsuch that the same guide piece can attach to the chassis in multipleorientations.

It is yet another aspect of the invention that the guide piece may beinstalled and removed without the use of tools. It is still yet anotheraspect of the invention that the same guide piece may be used a multipleof times, being installed and removed over and over again.

A further aspect of the invention is a guide piece that does not requireprotrusions through the chassis for attachment purposes.

A still further aspect of the invention is a guide piece that does notrequire the use of snaps, rivets, or other attachment devices. A furtheraspect of the invention is a guide piece that does not require clearanceon any external chassis surface for attachment or removal purposes.

Another aspect of the invention is a guide piece that does not requireaccess to any external surfaces of the chassis for installation orremoval.

A still further aspect of the invention is a guide piece may be easilymounted into a corner or offset corner of a chassis.

The above and other aspects of the invention are accomplished with aguide piece molded out of a rigid but slightly resilient material, suchas plastic. The guide piece has an elongated body with a U-shapedchannel extending down the entire length of the guide piece, wherein theU-shaped channel forms an opening on each end of the guide piece. ThisU-shaped channel is used to hold an edge of an electronic circuit card.At least one such guide piece is attached internally to a chassis sothat an edge of an electronic circuit card may be received into theU-shaped channel of the guide piece, thus helping to secure theelectronic circuit card in its proper place inside the chassis. Theguide piece thus allows for easy installation and removal of electroniccircuit cards for repair, testing, or replacement purposes.

The guide piece has a plurality of raised tabs along the externalsurface of one leg of the U-shaped channel and a plurality of middle andend nubs on the external surface of the other leg of the U shapedchannel.

The raised tabs are designed to mate with fingers that have been formedinto the chassis. The middle and end nubs are designed to mate with cutouts in the chassis. The combination of the raised tabs mating withfingers and the middle and end nubs mating with cut outs secures theguide piece to the chassis.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other aspects, features, and advantages of the inventionwill be better understood by reading the following more particulardescription of the invention, presented in conjunction with thefollowing drawings, wherein:

FIG. 1 shows a perspective view of one side of the guide piece;

FIG. 2 shows a second perspective view of the other side of the guidepiece;

FIG. 3 shows a perspective view of a typical corner of a chassis withfingers and middle nub holes and end nub holes;

FIG. 4 shows a perspective view of a guide piece that has been cornermounted on the chassis shown in FIG. 3;

FIG. 5 shows a cross section in plan view of a guide piece as it isbeing attached in the orientation shown in FIG. 4;

FIG. 6 shows a perspective view of a guide piece that has been mountedon a chassis with a corner offset;

FIG. 7 shows a perspective view of a guide piece that has been mountedon a chassis in an interior location with a vertical orientation;

FIG. 8 shows a perspective view of the guide piece in FIG. 7 from theopposite side;

FIG. 9 shows a perspective view of the guide piece that has been mountedon a chassis in an interior location with a horizontal orientation;

FIG. 10 shows a perspective view a raised tab;

FIG. 11 shows a perspective view of an end nub; and

FIG. 12 shows a perspective view of a middle nub.

DESCRIPTION OF THE PREFERRED EMBODIMENT

The following description is of the best presently contemplated mode ofcarrying out the present invention. This description is not to be takenin a limiting sense but is made merely for the purpose of describing thegeneral principles of the invention. The scope of the invention shouldbe determined by referencing the appended claims.

FIG. 1 shows a perspective view of a guide piece of the presentinvention. Referring now to FIG. 1, guide piece 10 is comprised of anelongated body 12 with a U-shaped channel 18 extending down the entirelength of elongated body 12 forming end openings 16 on either end. Inthe preferred embodiment the end openings 16 are beveled at anapproximate angle of 9.46° to allow for easier insertion of an edge ofan electronic circuit card.

An outer surface 20 extends down the length of one leg of U-shapedchannel 18. A plurality of raised tabs 14 are located along and moldedinto outer surface 20. One skilled in the art will recognize that inaddition to being molded into the guide piece, the raised tabs 14 couldalso be attached or affixed to external surface 20 of elongated body 12with glue or adhesive. Raised tabs 14 are L-shaped with one leg of the Loriented parallel to outer surface 20 and extending towards U-shapedchannel 18 and the other leg of the L extending substantiallyperpendicular to outer surface 20. In the preferred embodiment, each legof raised tabs 14 has a flat surface whose side edges are beveleddownward at an angle from the flat surface (as more fully shown in FIG.10), to allow for easier mating when attaching guide piece 10 to achassis (not shown in FIG. 1). The one leg of the L oriented parallel toouter surface 20 has side edges beveled downward at an approximate angleof 18.43°. The other leg of the L extending substantially perpendicularto outer surface 20 has side edges beveled downward at an approximateangle of 25.0°.

FIG. 2 shows another perspective view of guide piece 10. Referring nowto FIG. 2, an outer surface 26 extends down the length of the other legof U-shaped Channel 18. A plurality of middle nubs 22 are locatedbetween the ends of outer surface 26. In the preferred embodiment, themiddle nubs 22 are beveled at an approximate angle of 16.36° in thedirection towards U-shaped channel 18 (as more fully shown in FIG. 12)to aid installation. Also located on outer surface 26 at each end areend nubs 24. In the preferred embodiment, the end nubs 24 are beveled atan approximate angle of 18.45° in the direction towards the end of theguide piece 10 (as more fully shown in FIG. 11) to aid in removal of theguide piece. One skilled in the art will recognize that in addition tobeing molded into the form, middle nubs 22 and end nubs 24 could also beattached or affixed to external surface 26 of elongated body 12 withglue or adhesive.

FIG. 3 shows a perspective view of the inside corner of a typicalchassis 34. Referring now to FIG. 3, end nub holes 30 are cut out frombottom 31 of chassis 34 for receiving end nubs 24. Middle nub holes 28are cut out from bottom 31 of chassis 34 for receiving middle nubs 22.Middle nub holes 28 may also be sized only slightly larger than middlenubs 22. Fingers 32 are formed in adjacent side 33 of chassis 34 formating with raised tabs 14.

Referring now to FIG. 4, guide piece 10 is shown attached to chassis 34shown in FIG. 3. Attaching guide piece 10 in this orientation, whereinU-shaped channel 18 faces horizontally with respect to bottom 31 ofchassis 34, comprises positioning guide piece 10 so that outer surface26 faces down, outer surface 20 faces up, and U-shaped channel 18 faceshorizontally away from adjacent side 33 of chassis 34. Guide piece 10 isplaced flush with adjacent side 33 and bottom 31 of chassis 34 withraised tabs 14 on one side of fingers 32. Another way to describe thisis to position guide piece 10 such that raised tabs 14 are beside andoffset to fingers 32. Guide piece 10 is then moved laterally to orientraised tabs 14 under and behind fingers 32.

FIG. 5 shows a cross section of guide piece 10 being attached to chassis34 in the horizontal orientation shown in FIG. 4. Guide piece 10 ispositioned flush against adjacent side 33 and bottom 31 of chassis 34and moved laterally in the direction indicated by directional arrow 35.One skilled in the art will recognize that for installation guide piece10 may also be positioned with raised tabs 14 on the opposite side ofFingers 32 as shown in FIG. 5 and moved in a lateral direction oppositeto that indicted by directional arrow 35.

As raised tabs 14 begin contact along their beveled edges with Fingers32, the middle portion of guide piece 10 is forced down, flexing guidepiece 10 into a mild bow shape, and middle nubs 22 begin to seat inmiddle nub holes 28. End nubs 23 and 24 are still resting on the uppersurface of bottom 31 of chassis 34. As guide piece 10 is further movedlaterally in the direction indicated by directional arrow 35, end nubs23 and 24 seat into end nub holes 29 and 30, snapping down into placedue to the tension in the flexed guide piece 10. Snapping into placerelieves the flexed bow shape of guide piece 10 and raised tabs 14become fully mated with Fingers 32, and middle nubs 22 and end nubs 23and 24 fully seat with middle nub holes 28 and end nub holes 29 and 30respectively.

To remove guide piece 10 from chassis 34 from the horizontal orientationshown in FIG. 4 and FIG. 5, front end 27 of guide piece 10 is liftedvertically to allow end nub 24 to clear end nub hole 30. After beinglifted, guide piece 10 is moved laterally in the opposite directionindicated by directional arrow 35 of FIG. 5. As guide piece 10 is liftedand moved, trailing end 25 of guide piece 10 slides along the beveledsurface of end nub 23 up and out of end nub hole 29. When raised tabs 14pass completely from behind and under fingers 32, guide piece 10 maythen be fully removed from chassis 34.

Referring now to FIG. 6, guide piece 10 is shown attached to chassis 37in a corner offset in a horizontal orientation. Raised tabs 14 are matedwith fingers 39 formed in the corner offset. Middle nubs 22 and end nubs24 are seated respectively in middle nub holes 28 and end nub holes 30(not shown). Guide piece 10 is attached and removed in this corneroffset position in the same manner as described above with respect toFIG. 5.

Referring now to FIG. 7, guide piece 10 is shown attached to chassis 41in an interior location with a vertical orientation wherein U-shapedchannel 18 faces up. Raised tabs 14 are mated with fingers 43 formed inbottom 42 of chassis 41.

Referring now to FIG. 8, guide piece 10 as shown in FIG. 7 is shown in aperspective view from the opposite side. A plurality of C-brackets 36are formed in bottom 42 of chassis 41 wherein each C-bracket will seatwith a middle nub 22. O-shaped brackets 38 are formed in bottom 42 ofchassis 41 wherein each O-shaped bracket will seat with an end nub 24.Guide piece 10 is attached and removed in this interior location with avertical orientation in much the same manner as described above.

Referring now to FIG. 9, guide piece 10 is attached to chassis 44 in aninterior location with a horizontal orientation. Raised tabs 14 aremated with a plurality of slotted brackets 40 formed in bottom 45 ofchassis 44 leaving cut outs 47. Middle nubs 22 and end nubs 24 areseated respectively in middle nub holes 28 and end nub holes 30 (notshown).

Attaching guide piece 10 in this interior location comprises positioningguide piece 10 in a slightly rotated orientation so that outer surface26 faces generally toward, but is not parallel to bottom 45, outersurface 20 faces generally away from bottom 45, and U-shaped channel 18faces generally horizontally away from slotted brackets 40. Guide piece10 is positioned so that the tops of raised tabs 14 pass under theforward portions 46 of slotted brackets 40 and engage in the widerportions 48 of slots 50. Guide piece 10 is then rotated so that theextended legs of raised tabs 14 become vertical with respect to bottom45 of chassis 44, and outer surface 26 becomes horizontal with respectto bottom 45 of chassis 44, resting upon end nubs 24 with middle nubs 22positioned above middle nub holes 28 (not shown). Middle nubs 22 aid inthis rotation process due to their beveled surfaces that contact withbottom 45 of chassis 44. Guide piece 10 is then moved laterally in thedirection indicated by directional arrow 52. As the beveled portions ofboth legs of raised tabs 14 come in contact with the narrower portions54 of slots 50 in slotted brackets 40, the middle portion of guide piece10 is forced down, flexing guide piece 10 into a mild bow shape, andmiddle nubs 22 begin seating in middle nub holes 28 (not shown). Endnubs 24 (not shown) are still resting on the upper surface of bottom 45of chassis 44. As guide piece 10 is further moved laterally in thedirection indicated by directional arrow 52, end nubs 24 seat in end nubholes 30 (not shown), snapping down into place due to the tension of theflexed guide piece 10. Snapping into place relieves the flexed bow shapeof guide piece 10 and raised tabs 14 become fully mated with slottedbrackets 40 and middle nubs 22 and end nubs 24 become fully seatedrespectively with middle nub holes 28 and end nub holes 30 (not shown).

To remove guide piece 10 from chassis 44 from the horizontal orientationshown in FIG. 9, front end 56 of guide piece 10 is lifted vertically toallow end nub 24 to clear end nub hole 30 (not shown). After beinglifted, guide piece 10 is moved laterally in the opposite direction fromdirectional arrow 52. As guide piece 10 is lifted and moved, trailingend 58 of guide piece 10 slides along the beveled surface of end nub 24up and out of end nub hole 30 (not shown). When raised tabs 14 pass intowider portion 48 of slots SO of slotted brackets 40, guide piece 10 isthen rotated in the opposite direction from installation. As raised tabs14 pass below and away from forward portions 46 of slotted brackets 40,guide piece 10 may then be fully removed from chassis 44.

The method of installation and removal as described above in referenceto FIG. 9 may also be used in installation and removal in reference toFIG. 4 and FIG. 5, FIG. 6, and FIG. 7 and FIG. 8. However, this rotationmethod in reference to FIG. 9 is not as optimal as the methodspreviously described for these other orientations in FIG. 4 through FIG.8.

Referring now to FIG. 10, a portion of guide piece 10 is shown whereinraised tab 14, located on outer surface 20, has two flat surfaces 60 onthe interior side of each raised tab leg adjacent and perpendicular toeach other. Extending out from each flat surface 60 are exterior bevelededges 62 which aid installation by allowing raised tabs 14 to slidealong the beveled edges 62 against Fingers 32 (not shown in FIG. 10) toseat on flat surfaces 60.

Referring now to FIG. 11, a portion of guide piece 10 is shown whereinend nub 24, located on outer surface 26, has a beveled top surface 68angled away from outer surface 26 in a same direction as a longdimension of guide piece 10. One skilled in the art will recognize thatthe orientation of end nub 24 may be reversed, requiring oppositelateral movements from those described above for installation andremoval of guide piece 10 from a chassis.

Referring now to FIG. 12, a portion of guide piece 10 is shown whereinmiddle nub 22, located on outer surface 26, has a beveled top surface 64angled away from outer surface 26 forming a side of longest dimension 66that is perpendicular to outer surface 26 and faces towards U-shapedchannel 18.

Having described a presently preferred embodiment of the presentinvention, it will be understood by those skilled in the art that manychanges in construction and widely differing embodiments andapplications of the invention will suggest themselves without departingfrom the scope of the present invention, as defined in the claims. Thedisclosures and the description herein are intended to be illustrativeand are not in any sense limiting of the invention, defined in scope bythe following claims.

What is claimed is:
 1. A method of attaching a guide piece to a chassisin multiple orientations, said method comprising the steps of:(a)positioning said guide piece to allow each of a plurality of raisedtabs, each having at least one beveled edge, and each located on a firstouter surface of said guide piece, to align beside and offset from oneof a plurality of fingers formed in a first side of a corner of saidchassis; and (b) moving said guide piece laterally to cause each raisedtab to pass behind and under a one of said fingers with which eachraised tab is aligned, wherein said at least one beveled edge of eachraised tab first contacts said one of said plurality of fingers toassist said each raised tab in passing behind said one of said pluralityof fingers, comprising the steps of (b1) moving said guide piecelaterally to cause said plurality of fingers to begin contact with eachraised tab along an exterior beveled edge of a raised tab leg of eachraised tab, wherein as said plurality of fingers contact said exteriorbeveled edge, said guide piece is forced down, flexing said guide pieceinto a bow shape, and (b2) moving said guide piece laterally to cause anend nub, located on a first end of a second outer surface of a secondside of said guide piece and adjacent said first side of said corner, tosnap down into an end nub hole formed in said chassis, wherein said bowshape of said guide piece is relieved when said end nub enters said endnub hole.
 2. A method of attaching a guide piece to a chassis inmultiple orientations, said method comprising the steps of:(a)positioning said guide piece to allow each of a plurality of raisedtabs, each having at least one beveled edge, and each located on a firstouter surface of said guide piece, to align beside and offset from oneof a plurality of fingers formed in a corner offset in said chassiswherein said fingers are formed in a first side of said corner offset ofsaid chassis; and (b) moving said guide piece laterally to cause eachraised tab to pass behind and under a one of said fingers with whicheach raised tab is aligned, wherein said at least one beveled edge ofeach raised tab first contacts said one of said plurality of fingers toassist said each raised tab in passing behind said one of said pluralityof fingers, comprising the steps of(b1) moving said guide piecelaterally to cause said plurality of fingers to begin contact with eachraised tab along an exterior beveled edge of a raised tab leg of eachraised tab, wherein as said plurality of fingers contact said exteriorbeveled edge, said guide piece is forced down, flexing said guide pieceinto a bow shape, and (b2) moving said guide piece laterally to cause anend nub, located on a first end of a second outer surface of said guidepiece to snap down into an end nub hole formed in a second side,adjacent to said first side of said corner offset in said chassis,wherein said bow shape of said guide piece is relieved when said end nubenters said end nub hole.
 3. A method of attaching a guide piece to achassis in multiple orientations, said method comprising the stepsof:(a) positioning said guide piece in a slightly rotated orientation toallow each of a plurality of raised tabs, located on a first outersurface of said guide piece, each of said raised tabs having a raisedtab leg, to align with a plurality of slotted brackets formed in achassis, each said raised tab leg passing under a forward portion ofeach of said slotted brackets and engaging a wider portion of a slotformed in each of said slotted brackets; (b) rotating said guide pieceto cause said raised tab legs to orient to a vertical position withrespect to said chassis, said guide piece further having a plurality ofmiddle nubs affixed to a second outer surface, wherein each middle nubof said plurality of middle nubs has a beveled top surface, wherein saidbeveled top surface contacts said chassis, aiding in the rotation ofsaid guide piece to said vertical position; and (c) moving said guidepiece laterally to cause each raised tab leg to enter a narrower portionof said slot.
 4. The method of claim 3 wherein step (c) furthercomprises the steps of:(c1) moving said guide piece laterally to causesaid narrower portion of said slot to begin contact with each raised tabalong an exterior beveled edge of said raised tab leg of each raisedtab, wherein as said narrower portion of said slot contacts saidexterior beveled edge, said guide piece is forced down, flexing saidguide piece into a bow shape; and (c2) moving said guide piece laterallyto cause an end nub, located on a first end of a second outer surface ofsaid guide piece to snap down into an end nub hole formed in saidchassis, wherein said bow shape of said guide piece is relieved whensaid end nub enters said end nub hole.
 5. The method of claim 4 whereinstep (c1) further comprises the following step (c1a):(c1a)forming saidslotted brackets and said end nub hole in a same side of said chassis.